Isolation of a growth factor stress-induced pancreatic cancer sub-population: insight into changes due to micro-environment

Abstract

Background: Micro-environment plays a crucial role in determining the phenotypes within a tumor.

Materials and methods: In order to understand how the micro-environment affects pancreatic cancer, KLM1 cells were cultured under growth factor stress by culturing in foetal bovine serum (FBS)-free and reduced (1%) medium over several passages to mimic the core of a solid tumor with low vascularisation.

Results: Proteomic analysis on these conditioned pancreatic cancer cells, called KLM1-S, compared to the parent cell line KLM1 revealed that a number of proteins including α-enolase, GAPDH, GRP78, HSP60 and STIP-1 were dysregulated. Additionally, KLM1-S cells exhibited a 250-fold increase in half-maximal inhibitory concentration (IC50) over the parent cell line KLM1.

Conclusion: By decreasing their replication rate and levels of intracellular reactive oxygen species (ROS), KLM1-S cells are able to resist gemcitabine (GEM). The results obtained suggest that in KLM1 different phenotypes are a result of cellular plasticity rather than a committed transformation.

Keywords: Pancreatic cancer; cancer sub-population; micro-environment; proteomics.